Lumber mills process logs into material such as lumber pieces. The mills have many stations that perform different operations on the logs and the resulting lumber pieces generated from the logs. The lumber pieces as they exit one station are conveyed to a next station where further processing on the lumber pieces is performed. The lumber pieces are thus conveyed from one processing station to the next.
One of the objectives in the conveyance of the lumber pieces from station to station is to establish the proper orientation of the lumber pieces for the next processing station. For example, certain processes require the lumber pieces to be conveyed laterally, i.e., crossway to the direction of conveyance and it is desirable or even necessary in most cases that one end of the lumber pieces be positioned in a specific travel path as they enter the processing station. A common method for end positioning the lumber pieces (referred to as "even ending") is to provide a side board or fence along the side of the conveyor and providing side shifting of the lumber pieces into the fence.
One type of conveyor utilized in conveying the lumber pieces is the lug type conveyor that has upstanding lugs that engage the side edge of the lumber piece to be conveyed. The lumber pieces are thus placed cross way on the conveyor and are conveyed in this manner to the next station. The position of the lumber pieces on the conveyor most likely will vary from piece to piece. The lumber pieces thus must be moved transverse to the travel direction of the conveyor for abutment against a fence to properly position each lumber piece in the desired position for the subsequent processing station.
Existing conveyors have utilized long rollers having their rotational axis substantially parallel to the direction of conveyor movement. The rollers are rotated, e.g. by a motor to urge movement of the pieces crossway to the direction of conveyor movement. The length of the rollers insures sufficient contact with the pieces as they are also being conveyed by the lugs of the conveyor to achieve the desired lateral movement, that is, so the ends of the lumber pieces each have an end in abutment with a known register. The long rollers are mounted in the conveyor so that the rolls will just engage the underside of the lumber piece as it is being conveyed by the lug type conveyor. The powered rollers are initially expensive, requiring some manner of powering the rollers e.g. by individual motors, and also incur added maintenance expense over the life of the conveyor.
The present invention provides transverse positioning of the lumber pieces to align or even end the lumber pieces without the expensive powered rollers of the past.